Shortcuts work when the cockpit itself has focus — click any pane header or the top bar first. Once you click inside an app, that app has the keyboard.
Alt1–4 focus a pane
AltM maximize the focused pane / restore
Esc restore from maximized
AltR refresh the focused pane
AltH hide or show the top bar
Alt= / Alt- / Alt0 zoom the focused pane in / out / reset